Improvement in electric lights



ExAMlNEf gus. coMPoslTloNs,

Cross l Reference CDATING on msm '7 4 mqctrio Light.

Patented Mar. 4, 1879.

figure Wx'wms.

UNITED STATES' PATENT OEEICE CYPRIEN M. Tassin DU jMoTAY, 0F PARIS, FRANCE, AND EDWARD STERN,

oF NEW YORK, N. Y.

IMPROVEMENT IN ELEGTRIC LIGHTS.

Speeilieation forming part of Letters Patent No. 212,860, dated March 4, 1879; application tiled December 2, 1878.

Vper-eil or rod of the substances hereinafter named which will replace the carbon pencil in ordinary use, and which will be less expensive, burn longer in the saine length of peueil, and give a better light.

Earthy niattcrssuch as the oxides of zirconiuln, magnesium, calcium, carium, strontium, silicium, alumini um,`&c., ora mixture ofthembecome sufficiently good electrical conductors to produce an electric'arc oi' white light when they are prepared in the manner herein described, aud are united either with iron, with nickel, with platinum, or with any ofthe other metals allied to spongy platinum.

XVe prepare these pencils, which surround metallic conductors, in the following way: We lient to a red-orange heat the hydrated oxides or thc silicates, or a mixtureof tllcse so-called oxides, and after allowing. them to cool we pulverize them, and, if necessary, sift them. After that we kuead them with sticky adherent substances, either organicsuch as sirup, sugar, gum'dextrin u resinous materials, binding substances, or fat bodies, or other similarsubstauces--or inorganicsuch as silicates, alkalies, onychlorides of magnesium, zinc, &c. "ei'orui in this way a plastic paste, which we form or mold around amctallic conductor, either by hand or by mechanical means.- This paste is afterward dried either in the open air, or in a stove, or in a red-hot cruciblc. When it has become porous it furnishes an electric pencil ha vin g the physical properties of carbon pencils. and to be used in the same way.

Our pencil isclearly shown iu the accompanying drawings, in which Figures l and 2 represent views of our pencil for producing thc electric are.

B represents the-pencil in Figs. 1 and 2. A represents the conducting-wire.

This arrangement will maintain an electric arc between separated points iu precisely the saine manner as carbon pencils have prcvi ously donc. j By means of the metallic conductor, which is rapidly volatilized by the heat of the flame, we carry up the electric current without appreciable resistance to the initial point of the arc. If sufficient pressure is used in forming .the pencils the binding or sticky material may be dispensed with.

\Ve do not claim iu this application pencils consisting of powdered carbon attached to a central 'conductor by some cement, our pencils being composed of different material and being,r more advantageous than the carbon pencils heretofore used, from the following facts: Being composed of light-colored substanccsinstead of black, they are better suited for reflecting and giving forth the electric light; secondly, they produce a better light by a less expenditure oi' current; thirdly, they -are much less expensive than the ordinary carbon pencils, which are prepared with great difficulty and are liable to considerable variation in the compounds of which they are composed. 'lhese pencils are readily prepared of uniform quality throughout, and consequent] y the flickering of the light, which is due to thel presence of foreign material in the carbon pen cils, is avoided; and, lastly, our pencils last very much longer than the carbon pencils, which become rapidly disintegrated aud consumed.

One of our pencils will burn three to four times as long as a carbon pencil of the same size, which is a matter of the utmost importance in the practical operation of the electric light, because one of the principal di tlieulties in producing the electric light practically is to adjust properly the ends ot' .the pencils as thcyare consumed, and the. less adjustment which has to he done the more successful is the pencil. b n

What we claim as our invention, and desire t0 secure by Letters Patent, is-

l. rlhe herein-described electricpeucil, which consists of a rod or pencil formed of powdered earthy metter molded or shaped into a conducting-pencil by means cf some combining substance, substantially as and for the purunited by combining substance, substantxally as described.`

3.. Theherein-described electric pencilmhich` consists of an earthy oxide formed into a con.

ducting rod or pencil, and capable of maintaining the electric arc, substantially us described.

'. C. TESSIE DU MOTAY.

E. STERN. Witnesses:

Wn. S. Bmw, E. N. DlcimusoN, Jr. 

